In the wake of the COVID-19 pandemic many countries implemented containment measures to reduce disease transmission. Studies using digital data sources show that the mobility of individuals was effectively reduced in multiple countries. However, it remains unclear whether these reductions caused deeper structural changes in mobility networks and how such changes may affect dynamic processes on the network. Here we use movement data of mobile phone users to show that mobility in Germany has not only been reduced considerably: Lockdown measures caused substantial and long-lasting structural changes in the mobility network. We find that long-distance travel was reduced disproportionately strongly. The trimming of long-range network connectivity leads to a more local, clustered network and a moderation of the “small-world” effect. We demonstrate that these structural changes have a considerable effect on epidemic spreading processes by “flattening” the epidemic curve and delaying the spread to geographically distant regions.

COVID-19 大流行后，许多国家实施了遏制措施以减少疾病传播。使用数字数据源的研究表明，多个国家的个人流动性有效减少。然而，目前尚不清楚这些减少是否导致移动网络发生更深层次的结构变化，以及这些变化如何影响网络的动态过程。在这里，我们使用手机用户的移动数据来表明，德国的移动性不仅大幅下降：封锁措施还导致移动网络发生重大而持久的结构性变化。我们发现长途旅行大幅减少。远程网络连接的修剪导致网络更加本地化、集群化，并缓和“小世界”效应。我们证明，这些结构性变化通过“拉平”流行曲线并延迟向地理遥远的地区传播，对流行病传播过程产生了相当大的影响。